The invention relates to a device for processing a speech signal.
Such a device is known from patent document EP 0 633 520 A1, FIG. 3. In this device is provided a microphone as a speech signal input means and keys and input-wheels, and a touch-sensitive input tablet as control signal input means for inputting control signals. The known device is provided and arranged for co-operation with a base station, the base station in essence comprising a personal computer, a monitor and a keyboard while, in addition, also a so-called mouse can be provided. With the known device there is the problem that there must always be a communication link corresponding, in essence, to a line-of-sight link between the device and the base station to always have an interference-free cordless communication between the transmitter means of the device and the receiving means of the base station and to always ensure that speech signals input by the speech signal input means, thus the microphone of the device, can be transmitted to the base station. As soon as the interference-free communication link is interrupted in the known device, this will result in an interruption of the transmission of the speech signals input by the speech signal input means. This again leads to the fact that the speech signals input by the speech signal input means while the interruption of the interference-free communication link is taking place are not processed in the base station and not recorded either, although desired, if necessary.
It is an object of the invention to avoid in a simple manner the problems stated above and provide an improved device.
To achieve this object, such a device includes a speech signal input and speech signal digitizer, a control signal input and control signal digitizer, a digital signal processor, a transmitter to transmit processed digital signals in a cordless fashion to a base station, and a storage device, which is connected upstream of the transmitter and by which, depending on the quality of the communication link between the device and the base station, buffer the processed digital signals to be supplied and to be transmitted between the device and the base station.
In this manner there is achieved that with a device according to the invention speech signals input by the speech signal input means and digitized thereafter can always be buffered by the storage means and, after being buffered, be transmitted to a base station provided for co-operation with the device according to the invention. As long as a perfect communication link between the device according to the invention and a base station provided for cooperation with this device, speech signals which are input and digitized are buffered in the storage means and practically immediately thereafter, thus simultaneously, again read from the storage means and transmitted to the base station. Before a user of the device according to the invention leaves the room or area with the device in operation held in hand, which room or area is available for a perfect communication, the user can, for example, by manually actuating a key provided on the device according to the invention, interrupt the reading of buffered digital speech signals from the storage means and the subsequent transmission of these buffered digital speech signals to the base station, after which digital speech signals which are input are then buffered for a rather long bridging period, without these speech signals during this bridging period being read out from the storage means used as a buffer and transmitted to the base station. When, subsequently, the user again enters the room or area necessary for a perfect communication while he has the device in his hand during operation, the user can, for example, by keying-in a key, reactivate the reading of the digital speech signals buffered in the storage means during the said bridging period, so that then, after this bridging period, the buffered digital speech signals that have been read out are transferred to the transmitter means of the device and these digital speech signals are further flawlessly transmitted to the base station provided for this purpose.
In a device according to the invention it has proved to be advantageous when, additionally, the storage device is additionally provided for storing and reading digital control signals (DCS) to be transmitted, because in this manner not only digital speech signals, but also digital control signals can be buffered.
According to another aspect of the invention, a device according to the invention it has proved to be particularly advantageous when in lieu of the possibility of manually interrupting and starting the transmission of buffered digital speech signals from the device according to the invention to a base station provided for this purpose and automatic buffering is provided. They provide in a simple manner an automatic interruption and an automatic starting of the reading of buffered digital speech signals and, therefore, of the transmission of buffered digital speech signals from a device according to the invention to a base station provided for this purpose.
According to another aspect of the invention, a device according to the invention has been further proved to be highly advantageous when, additionally, the detection means includes an identification signal generator for generating an identification signal and the identification signal can be applied to the transmitter means and transmitted by the transmitter means to the receiving means of a base station is provided, because in this manner it is possible to reach a high accuracy of detection.
The aspects stated above and further aspects of the invention will be apparent from the examples of embodiment described hereinafter and explained with reference to these examples of embodiment.
The invention will be explained in the following with reference to two examples of embodiments shown in the drawings, to which, however, the invention is not restricted.